Analysis of toll station operations in Sri Lanka using a micro-simulation technique

The present manual toll collection system of Sri Lankan expressways is expected to be inadequate to serve the forecasted traffic demand on most interchanges. High waiting times at the manual toll booths would directly affect the expressway user delay and the level of service. Therefore, an efficient tolling system will have to be introduced. This study is focused on developing a methodology to evaluate the operational improvements of using electronic toll collection incorporating the traffic characteristics of Expressways in Sri Lanka. A micro-simulation method using a commercially available software; PTV Vissim, was adopted to conduct a scenario analysis for a forecasted traffic demand at the Kottawa interchange as a case study. A calibrated sample model was developed and its simulation results show that the electronic toll collection system can reduce the average per vehicle delay and increase the toll plaza capacity up to 50% during peak hour if the proper toll plaza configuration is provided. The findings of the study are beneficial to toll station operators as well as for planning for toll station upgrading by assessing its optimum capacity.